Manipulation of plants to alter and/or improve phenotypic characteristics (such as productivity or quality) requires the expression of heterologous genes in plant tissues. Such genetic manipulation relies on the availability of a means to drive and to control gene expression as required. For example, genetic manipulation relies on the availability and use of suitable promoters which are effective in plants and which regulate gene expression so as to give the desired effect(s) in the transgenic plant. Especially constitutive promoters are favored in situations where expression in all (or most) tissues during all (or most) times of the plant development are required. Examples of some known constitutive promoters which have been described include the rice actin 1 (Wang 1992; U.S. Pat. No. 5,641,876), CaMV 35S. (Odell 1985), CaMV 19S (Lawton 1987), nos, Adh, sucrose synthase; and the ubiquitin promoters. It is advantageous to have the choice of a variety of different promoters so that the most suitable promoter may be selected for a particular gene, construct, cell, tissue, plant or environment. Moreover, the increasing interest in cotransforming plants with multiple plant transcription units (PTU) and the potential problems associated with using common regulatory sequences for these purposes merit having a variety of promoter sequences available.
There is, therefore, a great need in the art for the identification of novel sequences that can be used for expression of selected transgenes in economically important plants. It is thus an objective of the present invention to provide new and alternative constitutive expression cassettes for constitutive expression of transgenes in plants. The objective is solved by the present invention.